1. Field of the Invention
The present invention relates generally to mobile navigation system and apparatus, and more particularly to a distributed navigation system having a wireless connection to a server for calculating optimal routes using real-time data.
2. Related Art
In recent years, navigation systems, in which automobiles are equipped with a navigational computer that includes a display screen, an input means such as a keypad or a remote control, and a storage means such as a CD, have become popular. Geographical map and routing data is typically stored on the CD. The map database on the CD can have various levels of detail. At the very least, the map database includes geographical information at the major road level. Additional details that can be included are minor roads, turn restrictions, one-way streets, highway ramp configurations, hotel, restaurant and other business information, traffic history, emergency facility locations and the like. The map databases with routing information are referred to as navigable map data or turn-by-turn data. The levels of detail stored on such databases depend on product and marketing factors, including cost and demand, as well as the physical storage capacity limitations.
Such navigation systems are stand-alone devices that rely completely on data stored on the local storage device for geographical and other information. Thus, the capacity of the storage device becomes a limiting factor as to how much information is available to users. In addition, users must update their mapping databases frequently to stay current. Typically, the cost of mapping databases increase with the amount of details provided thereon.
It would be desirable to have a navigation system that provides current information to users without the need to update their local databases whenever changes occur. In addition, it would be desirable to include real-time information such as traffic, weather and road conditions and the like for determining optimal routes. Further, it would be desirable to increase the level of details provided by current navigation systems without requiring expensive databases and/or databases that are beyond the capacity of the local storage device.
A current system, which connects to on-line servers in real-time, is Toyota's MONET navigation system implemented in Japan. The MONET system establishes a connection to the server that is responsive to requests for real-time information including current traffic conditions and the like. The server gathers the requested information and downloads the data to the client.
In this fashion, the MONET system, and other similar current systems, provide information and/or services to users in real-time. This information and/or services include real-time traffic data, road restrictions, email services, news, sports, and weather reports, points-of-interest data, and emergency information such as police, hospital and roadside assistance. These current systems also typically allow the user to download pictures of current traffic conditions, points of interest and the like.
In these current systems, all geographical data transmitted by the server is in a propriety format. That is, downloaded information used to describe geographical data, such as point-of-interest addresses and detailed map data, includes data points, indices and the like that are specific to the particular mapping database used on the client.
Accordingly, the client navigation system must have a particular pre-defined mapping database installed in order to work with the server. In some cases, the mapping database used by the client and server must be identical. If there is a mismatch between the expected mapping database and the actual mapping database used on the client, the client cannot properly interpret the geographical data downloaded from the server and the system will fail to operate.
Accordingly, customers using these current systems must obtain the latest version of the mapping database software available. This presents a major burden for customers and manufacturers alike due to the high frequency in which these databases must be updated.
In addition, the data downloaded by the client generally requires high bandwidth communication channels due the shear volume of data transmitted by these current systems. Such high bandwidth communication channels are expensive and may not be readily available in all areas. It would be desirable to develop a system that requires lower bandwidth communication channels than that required by these current systems.
Another problem with the current systems outlined above is that the client must include sophisticated algorithms for calculating optimal routes. In addition, these route-calculating algorithms in the client must be updated in accordance with current services and options available on the server. For example, if the server were updated to provide a new or modified feature to the client, the client must be specifically customized to support the new or modified feature. Thus, a very close coordination between the software installed on the server and the software installed on the clients must be maintained. This creates an additional economic burden for customers.
Another problem with the current systems is that the proprietary server cannot be used with navigation systems and mapping databases provided by other manufacturers. As stated, using current systems, client software must be frequently customized and very specific mapping software must be used. It would be desirable to have a navigation system that can be easily adapted to work with a variety of mapping software and navigational systems.